What is it?

A 3D printer produces a solid, real life, object from a computer imaginary representation. This can have been created by a program or as a result of scanning a real original. It is also called Solid Freeform Fabrication (SFF) or Additive Manufacturing.

What can it Make?

“Anything”, as long as it fits inside the machine, and is made of some castable material, typically plastic. There are also some limits on the thinness of items. On the cheaper models it is difficult to make shapes that require intermediate support. The accuracy (of a production machine) is around 0.1 mm, slightly better for some processes.

“Anything” could be a toy, a decoration, jewelry/accessory, a mechanical part (gear, lever, screw, nut, a hinge), a small household item (cup, salt shaker) and a spare part of something that broke (you can use a 3D printer that produce a metallic substance). With a little afterwork like polishing and painting, small wonders can be made.

By using sugar instead of plastic you can make sweets in (f.ex.) mathematical shapes. Using dough for an edible sculpture! Whatever material can be squeezed onto a surface building up in layers and hardened.

What can it not make?

The limit is the size of the machine, the accuracy of the smallest step, and most limiting is the material, which has to be something that melts and hardens, or powder you can fuse.. So you can not do anything electronic or clothlike or living. It can be small but not microscopic. The material is the same all the way through (some models allow you to use several different coloured plastic)

A print item takes half an hour or many hours. Although a 3D-printer could make lots of identical things, like a factory, the time (and cost?) make it most reasonable to make unique one-off items or just a few copies.